This invention relates generally to gas turbine engines, and more specifically to structural covers used with gas turbine engine bolted flanges.
At least some known gas turbine engines include a core engine having, in serial flow arrangement, a high pressure compressor which compresses airflow entering the engine, a combustor which burns a mixture of fuel and air, and a turbine which includes a plurality of rotor blades that extract rotational energy from airflow exiting the combustor.
Often components within the gas flowpath are coupled together using bolted flanges. Because of the velocity of air within the gas flow path, exposed fasteners in the bolted flanges may cause undesirable disruptions in the flow path downstream from the bolted flange. Such disruptions commonly known as windage, may adversely affect engine performance.
To facilitate eliminating windage caused by exposed fasteners, at least some known bolted flanges include a separate windage cover which extends over the heads or nuts of the fasteners to facilitate minimizing fastener exposure to the gas flowpath. However, because of the thickness of the covers, longer fasteners and an additional alignment flange must be used in comparison to those bolted flanges which do not include the covers. As such, installing such covers increases overall manufacturing assembly time, parts count, engine weight, and overall manufacturing costs.
In one aspect of the invention, a method for manufacturing a structural cover for a gas turbine engine is provided. The method comprises forming a torroidial body including an integrally-formed windage cover portion and a seal flange portion, and forming a plurality of fastener openings extending from a forward side of the torroidial body to an aft side of the torroidial body, such that when installed in the gas turbine engine, the windage cover portion facilitates shielding the fastener openings from a gas flow path.
In another aspect of the invention, a structural cover for a gas turbine engine is provided. The cover includes a torroidial body including an integrally-formed windage cover portion, a seal flange portion, and at least one fastener opening extending therethrough, wherein the windage cover portion is for shielding a fastener from a gas flow path.
In a further aspect of the invention, a gas turbine including a torrodial structural cover is provided. The cover includes an integrally-formed windage cover portion, a seal flange portion, and a plurality of fastener openings extending therethrough. The windage cover portion is configured to facilitate sheilding fasteners extending through the fastener openings from a gas flow path.